Fair Ukon Yatsurugi is an assassin and member of the Twelve Heavenly Generals of the Martial Fist. Narcissistic and honorable, Ukon is a samurai skilled in the fast-draw technique called Demonic Beheading. It's an art that takes brash Kyouichi Houraiji by surprise when the young General is set to kill the Magami delinquent.

Ukon has a deep admiration for all things beautiful, and a noble sense of justice. When he senses a change in tactics and spirit from Kyouichi, he has no qualms about forfeiting the assassination request and befriending Kyouichi instead. He later returns to aid in the battle against Yagyuu.

In the omake episode, Ukon Yatsurugi shows a great sense of care for Kureha Mibu, and the two seemingly remain comrades after everything.